U.S. Pat. No. 5,006,528 to Oshiro et al. discloses 7-[(4-phenylpiperazino)-butoxy]carbostyrils, which include aripiprazole, as dopaminergic neurotransmitter antagonists.
Aripiprazole which has the structure
is an atypical antipsychotic agent useful in treating schizophrenia. It has poor aqueous solubility (<1 μg/mL at room temperature).
U.S. Pat. No. 6,267,989 to Liversidge, et al. discloses a method for preventing crystal growth and particle aggregation in nanoparticulate compositions wherein a nanoparticulate composition is reduced to an optimal effective average particle size employing aqueous milling techniques including ball milling.
U.S. Pat. No. 5,314,506 to Midler, et al. relates to a process for the direct crystallization of a pharmaceutical having high surface area particles of high purity and stability wherein impinging jet streams are employed to achieve high intensity micromixing of particles of the pharmaceutical followed by nucleation and direct production of small crystals.
A long-acting aripiprazole sterile injectable formulation has merit as a drug dosage form in that it may increase the compliance of patients and thereby lower the rate of relapse in the treatment of schizophrenia. Examples of known long acting drug products for the treatment of schizophrenia include haloperidol decanoate and fluphenazine decanoate both of which have an ester compound of low water solubility dissolved in sesame oil. Microcapsules containing Risperidone (WO95/13814) and Olanzapine (WO99/12549) are also known.